How to Install Metal Roofing Over Shingles

When upgrading your home's roof, metal roofing stands out as one of the most durable and cost-effective options. If you live in Lincoln, Omaha, Grand Island, Denver, or Houston and are thinking about a roof cleaning and replacement, you might wonder if you can install metal roofing over your existing shingles. The answer is yes, and this method can save you time and money while providing great long-term value. 

At Murray Roofing, we have helped many homeowners in Nebraska, Colorado, and Texas make the switch to metal roofing. With over 80 years of combined experience and our GAF Master Elite Contractor status, we know how to install metal roofs properly. In this guide, we will cover everything you need to know about installing metal roofing over shingles.

Why Choose Metal Roofing Over Traditional Shingles?

Before starting the installation process, it's helpful to know why metal roofing is a popular choice for homeowners. Metal roofs are very durable, often lasting 40 to 70 years compared to the 15 to 25 year lifespan of asphalt shingles. They resist extreme weather, including hail, high winds, and heavy snow, which makes them a great fit for the different climates in our service areas.

Moreover, metal roofing is efficient. The reflective properties of metal roofs can lower cooling costs by up to 25% during hot summer months. This is especially useful for our customers in Houston and Denver. Metal roofs are also good for the environment, often made with recycled materials and fully recyclable at the end of their life.

Can You Install Metal Roofing Over Existing Shingles?

The short answer is yes. In most cases, you can install metal roofing directly over one layer of existing asphalt shingles. This method, called a "reroof" or "overlay," has several benefits compared to a full tear-off. However, you need to make sure your roof meets specific criteria before you proceed.

Building Code Requirements  

Local building codes differ by region, but most areas permit one layer of metal roofing over existing shingles, as long as the total roof layers do not exceed a certain limit, usually two layers. At Murray Roofing, we know the building codes well in Nebraska, Colorado, and Texas. Our team ensures that every installation meets or surpasses local requirements.

Structural Considerations  

Your roof’s structural integrity is very important. The existing roof deck must be in good shape and able to support the extra weight of the metal roofing system. While metal roofing is lighter than many other materials, the combined weight of the shingles and metal must still be within your structure’s load-bearing capacity. Our free 10-point inspection includes a detailed check out of your roof’s structural soundness. 

The Step-by-Step Installation Process

Installing metal roofing over shingles is a detailed process that needs professional skills. Here’s what the installation usually includes:

1. Professional Inspection and Assessment  

The first step is always a complete roof inspection. Our certified specialists look at your current roof for any damage, rot, or structural problems that could interfere with a successful overlay installation. We check for good ventilation, assess the state of your shingles, and evaluate the roof deck's strength. This inspection is free and carries no obligation.

2. Roof Preparation  

If your existing shingles are suitable for an overlay, we start preparation by making sure the surface is clean and free of loose debris. Any damaged or curled shingles are repaired or flattened to create a smooth base. We also solve any existing ventilation problems and ensure proper attic ventilation, which is important for the life of your new metal roof.

3. Installing Underlayment  

Even though we're working over existing shingles, the right underlayment is important. We lay down a high-quality synthetic underlayment or roofing felt over the shingles. This layer offers an extra moisture barrier and helps prevent possible condensation issues. The underlayment also provides a smooth, even surface for the metal panels. 

4. Installing Trim and Flashing  

Before adding the metal panels, we install all necessary trim pieces and flashing. This includes drip edges, rake trim, valley flashing, and any special flashings around chimneys, skylights, or other roof openings. Proper flashing is crucial to prevent water leaks and ensure your roof stays watertight for many years.

5. Metal Panel Installation  

We start installing the metal roofing panels from one side of the roof and move across. Each panel overlaps the previous one according to the manufacturer's guidelines, creating a weather-tight seal. We secure the panels using special fasteners made for metal roofing, which include rubber washers to prevent leaks. Our skilled crews make sure the panels are precisely aligned and securely fastened for maximum durability.

6. Ridge Cap Installation  

The last major step is adding the ridge cap, which covers the peak of your roof where the two slopes meet. Ridge caps also help with proper attic ventilation through ridge vents if needed. This part is important for both the appearance and function of your metal roof.

7. Final Inspection and Quality Assurance  

At Murray Roofing, we don’t consider a job complete until we conduct a thorough final inspection. We check every fastener, seam, and trim piece to ensure everything meets our high standards. We also clean your property completely, using magnets to pick up any stray fasteners or metal scraps.

When Tear-Off is Necessary

While you can often install metal roofing over shingles, there are times when a complete tear-off is a better choice. If your current roof has several layers of shingles, serious water damage, a damaged roof deck, or significant rot, you need to remove the existing roofing. Also, if your shingles are heavily cupped or curled, they won't make a suitable base for metal roofing. 

Our team will honestly evaluate your roof's condition during our free inspection and suggest the best solution for your situation. We focus on your long-term satisfaction instead of short-term savings. This commitment has helped us maintain an A+ rating with the Better Business Bureau over our 18-plus years in business.

The Murray Roofing Advantage

Choosing the right roofing contractor is as important as selecting the right roofing material. Murray Roofing, one of just 2% of contractors in North America with GAF Master Elite Contractor status, brings unmatched expertise to every project. Our certifications prove our dedication to ongoing training, proper licensing, and customer satisfaction. 

We back our work with solid warranties, including a 10-year labor warranty along with manufacturer warranties. For eligible projects, we also provide the respected 50-year GAF Golden Pledge warranty, giving you decades of peace of mind.

Financing Your Metal Roof Installation 

We know that a new roof is a big investment for your home. That's why Murray Roofing provides 100% financing options for qualified homeowners. Our flexible plans help you get the high-quality metal roof you want without putting a strain on your budget. We will work with you to find a payment option that fits your financial needs. 

We also offer free upgrades worth up to $1,500 on qualifying replacement projects, excluding new builds. From better warranties to top-quality materials, we go the extra mile to make sure you receive great value.

Ready to Make the Switch to Metal Roofing?

Installing metal roofing over existing shingles is a smart way to improve your home’s protection and curb appeal. However, it takes experienced professionals to do the job properly. At Murray Roofing, we provide high-quality metal roofing installations using top materials and a reliable process that homeowners in Lincoln, Omaha, Grand Island, Denver, and Houston trust. Schedule your free 10-point roof inspection for an honest, no-pressure assessment of your roof. Find out if metal roofing over shingles is the right solution for your home. Contact Murray Roofing today to book your free inspection. 

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